As society becomes more aware of the environmental impact of commonly used manufacturing materials and the increasing shortage of fossil fuels, federal, state and local governments are quickly passing regulations to safeguard the environment. Unfortunately, many efforts to improve the environmental impact of one area of industry leads to a dramatic environmental impact on another area.
For example, in order to reduce consumption of fossil fuels and their associated damaging byproducts, federal, state and local governments have passed stringent requirements to regulate fossil fuel consumption in the automobile and aircraft industry. In addition to governmental regulations, increasing fossil fuel prices drive aircraft and motor vehicle manufacturers towards new manufacturing materials and methods that reduce weight and thus fuel consumption. Industries have responded quickly to environmental regulations by introducing greater and greater quantities of various new, lightweight composite materials into their products.
The phrase "composite materials" encompasses a broad range of materials ranging from wood composites, such as plywood, to composites formed of plastic, organic or ceramic matrix systems reinforced with particulate or fibrous reinforcement materials. Common composite fibrous material reinforcements include fiberglass fibers, graphite fibers, Kevlar.RTM. fibers, nylon fibers, etc.
Composite materials are themselves an increasing environmental problem. Some of the plastic, epoxy or ceramic matrix systems used in the manufacture of composite materials are harmful to the environment. Many plastic, epoxy and ceramic composite matrix systems are toxic to both plants and animals when in an uncured state. In addition, some composite matrix materials break down into toxic elements as they decompose over time. Other composite matrix materials are relatively immune to oxidation and do not biodegrade, creating a disposal problem due to their long life. Many recent news articles have addressed the growing shortage of waste disposal sites in the United States. As the use of composite materials increases, they present an increasing burden on waste disposal sites.
As various industries, including the automobile and aircraft industry, expand their use of composite materials, concerns regarding the disposal of products made from composite materials is growing dramatically. Only recently have products incorporating composite materials reached the end of their useful life, thus increasing the quantity of composite materials being disposed of. Although the use of composite materials has increased dramatically on a tonnage basis, methods of disposing, recycling or reusing such composite materials are generally unavailable.
It is impossible to put an exact tonnage on the quantity of composite materials disposed of in the United States in one year. The Washington State Waste Characterization survey in 1993 published by the Department of Ecology, listed fiberglass generation alone as 3.6% of all of the material deposited in regulated landfills. Based on these statistics, it is within reason that millions of tons of composite materials are disposed of in landfills in the U.S. alone each year.
The disposal costs for disposing of cured composite materials can range between $90 to $250 per ton of waste. If the waste includes uncured plastic, epoxy or ceramic resins, it is necessary to dispose of the waste under hazardous waste handling regulations. Such hazardous waste materials are not disposable in standard landfills and must be disposed of at specially regulated hazardous waste disposal sites at an increased cost.
The environmental concerns associated with the disposal of composite materials are already on the rise. As the use of composite materials continues to increase in all areas of industry, the problems associated with disposal will grow accordingly unless action is taken to solve the problem now.
As can be seen from the above discussion, there exists a critical need in the industry for methods and apparatus to dispose of or recycle waste cured composite materials and waste uncured matrix material systems, such as plastic or epoxy resins. The present invention is directed toward addressing this need.